Exposition additional stuff

 

The Bearded Vulture

The Lammergeier or Bearded Vulture, Gypaetus barbatus (“Bearded Vulture-Eagle”), is an old world vulture – not related to nowadays most common vultures. Its the only member of the genus Gypaetus. It breeds on crags in high mountains in southern Europe, Africa, India, and Tibet, laying one or two eggs in mid-winter which hatch at the beginning of spring. The population is resident. The Lammergeier has been successfully re-introduced into the Alps, but is still one of the rarest raptors in Europe.

Like other vultures, it is a scavenger, feeding mostly from carcasses of dead animals. It usually disdains the rotting meat, however, and lives on a diet that is 90% bone marrow. It will drop large bone from a height to crack them into smaller pieces. Its old name of Ossifrage (“bone breaker”) relates to this habit. Live tortoises are also dropped in similar fashion to crack them open.

The Bearded vulture reaches 1.10 m in size (from head to tail), its wingspan is around 2.8 m and it weighs about 5-7 kg.

Where to find the Gypaetus Barbatus Barbatus in Europe.

It’s also found in other places of Europe. Nowadays there are about 77 pairs in the Pyrenees, in the island of Corsica there are 10 pairs and in the Balkans there are 2-3 pairs, while in the Alps, where the species has been reintroduced, there are 80 individuals and 4 pairs.
Other exemplars can be found in the isle of Crete (Greece).

The bearded vulture is, however, not in a serious risk of extinguishing. More exemplars can be found in large zones of Africa and Asia, divided into two sub-species: the Gypaetus Barbatus Barbatus and the Gypaetus Barbatus Meridionalis. The ones in Europe are Gypaetus B. Barbatus.

A little video, filmed in the Spanish Pyrenees.

http://www.youtube.com/watch?v=SRAiprmegXg

Last but not least, a webpage from Spain dedicated to help this noble animal

http://www.quebrantahuesos.org/htm/es/fcq/intro.htm

Cheers

 

Link

Such an obvious webpage. Ecology? Where?

In http://ecology.com/ecology-today/ . A good name for an ecology website, isn’t it?

Cheers.

 

Natural Selection in action

The teacher firstly explain the difficulty of pooving natural selection. Indeed, he menctions that most of the clear examples we can use are man-made! But he explains that natural selection in nature takes a long time.

He uses an hypothethical example about bacteria, and abaout how a single modification in the cell wall of a bacteria could enable that single individual to survive and reproduce while the others perished due to a medicine.

Then he tells us an example, a true story we’ve already menctioned in the classroom: the case of the pepper moths.

In a forest of white trees, peppered moths were less likely to survive than white moths, whick were better camouflaged and fitter; but some years after, in the industrial revolution, polution darkened the colour of the trees, making the white moths more easy to eat for birds and giving an advantage to black moths.

Finally he tells us to always ask the question “Why?” to our surroundings, like for example “Why is that horn curvy?” or “Why is there a spot on this fish head?” and searching or reasoning an answer.

Video: http://www.5min.com/Video/Natural-Selection-in-Action-150610695

Cheers

 

African Elephants are, surprisingly, one of the most adapted animals you can find. In fact, elephants can resist and endure long dry periods and survive in environments (as the African savannah) that are full of dangerous predators.

Some of the most impressive adaptation features in elephants are:

- The long trunk that acts as nose. This trump could have been developed to grab higher leaves, to drink water eassily or to smell better. This trumk is very sensitive. The first elephants had this trunk. Probably it was developed by mutation from a different specie of mastodons, as I don’t think variation can produce such a huge change. Then, that mutation could have helped that animal to reach food or drink water easily, and therefore eventually to have more descendants.

- The thick tought skin that African elephants have is useful to isolate the animal from extreame climate. Paquiderms usually have this type of skin. The characteristic could have been developed by variation and natural selection (the survival of the mammals with the thicker skin would eventually led to a full specie of paquiderms) or by mutation.

- The big ears the elephants have are used to lose heat from their bodies. That’s why they are so big and thin. This feature is specific from the African elephants, and I also think it could be mainly a good mutation.

- The long tusks that elephants have can be used to disuade predators. Naturally this tusks would be strange, as they are not used to eat. I also think this could have been generated by a sudden mutation and then helped the elephant to dig for roots or to fight.

It can be interesting to think how mammoths, which clearly resemble to elephants, were themselves adapted to their cold environment. However, elephants aren’t evolved from mammoths.

Cheers.

(Same of the sources below)

http://en.wikipedia.org/wiki/Elephant

http://www.principia.edu/mammoth/mammothfacts.htm

http://www.swbg-animals.org/animal-info/info-books/elephants/adaptations.htm

http://ezinearticles.com/?The-History-of-Elephants&id=587098

 

Doubts (Feb 15tf to Feb 21st)

- Sexual inheritance in birds.

As we saw the other day, humans have sexual inheritance. But there are two types of sexual inheritance, and most birds have a different type of sexual inheritance to develope the sex of their offspring.

In the type of sexual inheritance humans have, the male is heterozygous (XY) and the female is homozygous (XX) for a sex factor This type takes place in lots of living beings, and it is called Drosophilia.

On the other hand, there is another type of sexual inheritance, called the Abraxas type, in which the male is homozygous (ZZ) for a sex factor and the female is heterozygous (WZ). Most birds, incluiding chickens, ducks and canaries, have this type of sexual inheritance.

Anyway, the results of this two types are approximately the same, both meaning a 50% possibilities for both genders.

- Sexual inheritance in bees.

Bees have a very particular way of determining the gender of the new larvae. Recient experiments have prooved that the queen can decide to lay fertilized or unfertilized eggs. Unfertilized eggs will produce drones, while fertilized ones will produce females, workers and queens. This experiments have prooved that que queen deliverately mantains a balance between the two genders, changing the normal rate of fertilized eggs when we force or change the conditions.

The gene that determines the gender in bees is called the csd (complementary sex determination) gene.

In humans, sex is determined by the combination of sex-determining chromosomes one has. In females, both sex-determining chromosomes are the same – XX; for males the two chromosomes are different – XY. Bees do things a bit differently. Specific combinations of the csd gene regulate the gender and social roles of each bee.

If the bee has two different alleles, the csd gene will be female (it has two alleles because it was fertilized). If it has only a single version of the gene, it will become a normal, fertile male. Finally, if the bee has two identical csd types it will become a diploid male, which is infertile.

- Women with only one X.

The X chromosome carries a couple thousand genes, but few, if any, of these have anything to do directly with sex determination. Early in embryonic development in females, one of the two X chromosomes is randomly and permanently inactivated in nearly all somatic cells (cells other than egg and sperm cells). This phenomenon is called x-inactivation or lyonization, and creates a Barr-body.

Therefore, a Barr body is the inactive X chromosome in a female cell.

X-inactivation ensures that females, like males, have one functional copy of the X chromosome in each body cell. It was previously assumed that only one copy is actively used. However, recent research suggests that the Barr-body may be more biologically active than was previously supposed.

But, there are women that only have one X chromosome.

This condition is normally produced by the Turner syndrome, and it is called monosomy X.  The Turner syndrome is a problem that appears approximately in one of every 2500 women.

There are characteristic physical abnormalities, such as short stature, swelling, broad chest, low hairline, low set ears, and webbed necks. Girls with Turner syndrome typically experience gonadal dysfunction (non-working ovaries), which results in amenorrhea (absence of menstrual cycle) and sterility. Concurrent health concerns are also frequently present, including congenital heart disease, hypothyroidism (reduced hormone secretion by the thyroid), diabetes, vision problems, hearing concerns, and many autoimmune diseases. Finally, a specific pattern of cognitive deficits is often observed, with particular difficulties in visuospatial, mathematical, and memory areas.

- People with XXY.

¿Why some people have this strange genotype for their gender? The main reason, is a particular syndrome, called the Klinefelter’s syndrome.

Klinefelter’s syndrome is, therefore, a condition in which males have an extra X sex chromosome. While females have an XX chromosomal makeup, and males an XY, affected individuals have at least two X chromosomes and at least one Y chromosome. It is the most common sex chromosome disorder. The principal effects are development of small testicles and reduced fertility. A variety of other physical and behavioral differences and problems are common, though severity varies and many boys and men with the condition have few detectable symptoms.

That’s all folks;

Rubén Laplaza

 

to post images

First you need permission to do so from fernando, then try to post.

Then you’ll find an icon just THERE

You click and you’ll be ableto post images from an URL or fromyour own computer

enjoy

 

Monos salvajes

Sorry,i didn’t realise the signs

Just trying. Enjoy the monkeys.

 

Probably this makes little or no sense but . . .

Meiosis

Mitosis

Mitosis and meiosis videos in youtube.

Enjoy.

 

EARTHQUAKES (Rubén Laplaza)

(not corrected yet)

EARTHQUAKES.

WHAT IS AN EARTHQUAKE?

An earthquake is the result of a sudden release of energy in the Earth’s crust that creates seismic waves.

The point of initial rupture of an earthquake is called its focus or hypocenter. The term epicenter refers to the point at ground level directly above the hypocenter.

At the Earth’s surface, earthquakes manifest themselves as a sudden shaking and sometimes displacement of the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.

WHY EARTHQUAKES HAPPEN?

Along the boundary separating any two tectonic plates, there can be movement. Depending on the boundary, as you must know, this movement can be of crushing, pulling apart, or sliding past each other.

The movement between plates and along faults is not smooth. They move in jerks, crushing, sliding and compressing, giving rise to earthquakes. The locations of earthquakes throughout the world, not surprisingly, delineate the major tectonic boundaries. Its because earthquakes normally take place in this boundaries and faults.

Because faults have friction, they resist the forces trying to move the pieces apart. As the forces build, the fault remains locked and the blocks get deformed because of the increasing stress. Eventually the stresses get so high that the fault breaks. This releases the built up stress and allows the sides of the fault to slide past one another. This is what we call an earthquake.

SEISMIC WAVES

Earthquakes create seismic waves which shake the ground as they pass.

Seismic waves are waves of force that travel through the Earth or other elastic body. This waves are created in different ways, one of them, are earthquakes.

There are two main types of seismic waves, body waves and surface waves.

Body waves travel through the interior of the Earth, while surface waves are analogous to water waves and travel just under the Earth’s surface. Body waves are generally faster, but surface waves can be far more destructive. The main types of body waves are P-waves and S-waves, and the two main types of surface waves are Rayleigh waves and Love waves.

Body waves:

- P waves (primary waves) are longitudinal waves, which means that the ground is alternately compressed and dilated in the direction of propagation. In solids, these waves generally travel almost twice as fast as S waves and can travel through any type of material, solids, liquids and gases. When generated by an earthquake they are less destructive than the S waves and surface waves that follow them, due to their smaller amplitudes.

The movement of the ground is someway similar to that of a slinky.

- S waves (secondary waves) are transverse or shear waves, which means that the ground is displaced perpendicularly to the direction of propagation. S waves can travel only through solids, so they cannot spread throught the core of the earth.

The movement of the ground is someway similar to that of a shaked rope, perpendicular to the direction of the wave.

Surface waves:

- Rayleigh waves are surface waves that travel as ripples with motions that are similar to those of waves on the surface of water. They are slower than body waves, but they are much more destructives.

- Love waves are surface waves that cause horizontal shearing of the ground. They usually travel slightly faster than Rayleigh waves, about 90% of the S wave velocity.

The seismic waves that an eartquake causes can be detected with a sensitive instrument called a seismograph.

Seismograph sketch (old model).

The record of ground shaking recorded by the seismograph is called a seismogram. The type of seismograph represented in the sketch above is one of the many invented in the 19^th century. Most of them were electromagnetic and operated by suspending a magnetic mass, or pendulum, within an electric coil.

Seismogram example.

Nowadays, mainly digital seismographs are used.

HOW DO WE MEASURE EARTHQUAKES?

There are many ways to measure the size of an earthquake. Some depend on the amount of damage caused by the earthquake, which is a subjetive measure, while others depend on the amount of seismic energy emitted by the earthquake. The two main scales used are the Mercalli Intensity Scale and the Ritcher Magnitude Scale.

The Mercalli Intensity Scale

The Mercalli Intensity Scale assigns an intensity or rating to measure the effects of an earthquake at a particular location.

The Mercalli Intensity of any one earthquake can be very different from place to place. This is because the amount of damage caused by an earthquake at a particular location depends on the geology of the location. The population density, the methods used to construct buildings near the location, and the distance to the epicenter are also important in the Mercalli scale.

Although it is an opinionated measure of earthquake size, so it is not objective, seismologists still mail questionnaires to local residents after an earthquake asking them to rate the effects of the earthquake at their home.

The Richter magnitude scale

The Richter magnitude scale assigns a single number to measure the amount of seismic energy released by an earthquake.

It’s related to the maximum amplitude of the S wave measured from the seismogram. Because there is a great range in the sizes of different earthquakes, the Richter scale uses logarithms. This means a magnitude 7 earthquake is 10 times as large as a magnitude 6 earthquake, and releases over 30 times more energy.

This scale is an objective scale, giving exact data about the earthquake.

ADITIONAL DATA

Mercalli Intensity Scale (whole)

I. Instrumental	Not felt by many people unless in favourable conditions.
II. Feeble	Felt only by a few people at best, especially on the upper floors of buildings. Delicately suspended objects may swing.
III. Slight	Felt quite noticeably by people indoors, especially on the upper floors of buildings. Many do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibration similar to the passing of a truck. Duration estimated.
IV. Moderate	Felt indoors by many people, outdoors by few people during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rock noticeably. Dishes and windows rattle alarmingly.
V. Rather Strong	Felt outside by most, may not be felt by some outside in non-favourable conditions. Dishes and windows may break and large bells will ring. Vibrations like large train passing close to house.
VI. Strong	Felt by all; many frightened and run outdoors, walk unsteadily. Windows, dishes, glassware broken; books fall off shelves; some heavy furniture moved or overturned; a few instances of fallen plaster. Damage slight.
VII. Very Strong	Difficult to stand; furniture broken; damage negligible in building of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Noticed by people driving motor cars.
VIII. Destructive	Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture moved.
IX. Ruinous	General panic; damage considerable in specially designed structures, well designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.
X. Disastrous	Some well built wooden structures destroyed; most masonry and frame structures destroyed with foundation. Rails bent.
XI. Very Disastrous	Few, if any masonry structures remain standing. Bridges destroyed. Rails bent greatly.
XII. Catastrophic	Total damage – Almost everything is destroyed. Lines of sight and level distorted. Objects thrown into the air. The ground moves in waves or ripples. Large amounts of rock may move position.

Ritcher Magnitude Scale (whole)

Richter magnitudes	Description	Earthquake effects	Frequency of occurrence
Less than 2.0	Micro	Microearthquakes, not felt.	About 8,000 per day
2.0-2.9	Minor	Generally not felt, but recorded.	About 1,000 per day
3.0-3.9		Often felt, but rarely causes damage.	49,000 per year (est.)
4.0-4.9	Light	Noticeable shaking of indoor items, rattling noises. Significant damage unlikely.	6,200 per year (est.)
5.0-5.9	Moderate	Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings.	800 per year
6.0-6.9	Strong	Can be destructive in areas up to about 160 kilometres (100 mi) across in populated areas.	120 per year
7.0-7.9	Major	Can cause serious damage over larger areas.	18 per year
8.0-8.9	Great	Can cause serious damage in areas several hundred miles across.	1 per year
9.0-9.9		Devastating in areas several thousand miles across.	1 per 20 years
10.0+	Epic	Never recorded; see below for equivalent seismic energy yield.	Extremely rare (Unknown)

Earthquake location map

Note: There are some images, but i don’t know how to upload them. The text is mainly that.