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The Lammergeier or Bearded VultureGypaetus 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 😀

Such an obvious webpage. Ecology? Where?

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

Cheers.

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

– 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

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