Showing posts with label genetics. Show all posts
Showing posts with label genetics. Show all posts

Thursday, January 30, 2014

Are You Part Neanderthal? Check Your Hair and Teeth

Are you part Neanderthal? Of course we would never consider ourselves to be part brute but that is what our DNA is telling us. A majority of us have a few percentage points of Neanderthal DNA within our bodies. Ironically those things that make us look attractive like hair and teeth are more closely tied to our ancient ancestors. 

Studies in the journal Nature and Science help us think about human development from the beginning of time until now. It is believed the Neanderthal was a northern creature while humans came from Africa. Somewhere along the path they interbred and the Neanderthal died off. Apparently, the males were not so great at breeding when mixed. 

Human development appears to be on a continuum from the past to some marked point in the future. Each child creates a new genetic destiny based upon a historical past and develops something unique. As the environment changes, humans change with it to ensure they able to survive and pass on their genetic code. 

Neanderthals died off due to lack of communication skills and environmental adjustments. Modern language appears to be one of the most defining and beneficial aspects of social development. Where Neanderthals could run around in packs of a half dozen humans can now travel in the thousands.

Saturday, June 22, 2013

Discoveries in the Red Queen Hypothesis and Evolutionary Arms Race

Researchers have lent credibility to the concept of an evolutionary arms race. Charles Marshall, a biology professor and the director of the UC Berkeley Museum of Paleontology, states, “But we found that a decrease in the origin of new species is just as important as increased extinction rate in driving mammals to extinction.”(UC Berkely News Center, 2013) Their findings help highlight the concept that diversity loss of species is a sign that the environment has overwhelmed them.

This hypothesis was originally developed by Leigh van Valen who indicated that the probability of a species survival was based in its competitive abilities with the environment. The environment in this case is other species as well as the life sustaining resources like food and water. As species reproduces, they create opportunities to develop stronger adaptations (new forms) that are better aligned to environmental threats. Generally, the more a species reproduces the more successful it will be due to it s pace of adaptation. Is it any wonder cockroaches are one of the strongest bio-groups in the world?

Often called The Red Queen Hypothesis it helps explain why species often grow and then fundamentally collapse into extinction. Based off of the a character in the book “Through the Looking Glass” by Lewis Carroll which describes the Red Queen’s explanation to Alice of Wonderland, “it takes all the running you can do, to keep in the same place.” Researchers have confirmed that the concept of evolution as a continuous evolving entity for survival was correct.

Results reported in the June 20th, 2013 Journal of Science Express indicate that species must continuously adapt to a declining environment by developing new forms or they themselves will become extinct. As the species reaches its environmental carrying capacity it  begins to decline as predators and lack of resources take their toll. Species compete against a host of other species in the environment and continue to change to protect themselves and spread their genetic material.

The researchers studied 19 mammals and found that many of them had their origins from around 66 million years ago. Their histories indicate a wide variety of related species. As their diversity decreases it also mirrors the decline in their over species because they cannot adapt to the overall environmental difficulties. It helps people understand that the system is never in full equilibrium and must increase or decline.

Taking a historical perspective allows for analysis over a greater time. Historical footprints such as fossils of previous adaptations with comparison to existing creatures helps to show how a particular species has grown or declined based upon its biodiversity. The more variability in its genetic diversity the stronger the survival probability when the environment changes. In the case of horses and elephants, the biodiversity is decreasing which means that they are less able to adapt to the modern environment. Humans are not immune to these adaptations and will continue to develop new forms of life to compete not only against other species (i.e. parasites and bacteria) but also the environment itself (overcrowding, global warming, food shortage, etc…).