Genetic Adaptations To Diving Discovered In Humans For The First Time
Showing posts with label genetic adaptation. Show all posts
Showing posts with label genetic adaptation. Show all posts
Friday, December 3, 2021
Genetic adaptations to diving discovered in humans for the first time
Tuesday, February 17, 2015
Darwin's Finches Get Their Genomes Sequenced
As the story goes, Darwin observed the physical characteristics of the finches and noticed that their beaks were adapted to the types of food they ate; for example, some had thin, sharp beaks for collecting pollen and nectar (like the Cactus finch), while other had strong, thick beaks for cracking nuts (like ground dwellers such as the Large ground finch). It's a prime example of "adaptive radiation", where a species deviates from a single ancestor as a response to selective pressures, and new species emerge.
With the tremendous amount of progress made in DNA sequences and genetic testing, geneticist Leif Andersson along with a team of scientists, analyzed samples from 120 birds and were able to redraw the family tree of the finches, connecting the dots between branches and indicating gene exchange. The team discovered mixing of genes between species, indicating crossbreeding, and "were able to pinpoint the genes responsible for beak morphology." One of the genes, ALX1, is known to control facial development in vertebrates. This is one of the genes that helped finches rapidly adapt their beak structures to the environment. This was seen as recently as the 1980's, where a drought changed the food supply and the birds had to adapt.
Other scientists have pointed out that beaks differ in many more ways than just being pointed or blunt. However, studying the ALX1 gene even further will reveal exactly what the gene controls, in this case, specialized beaks.
I really enjoyed this article because Darwin's finches experiment has always fascinated me and when combined with modern genetic technology, it's really exciting to find out what controls variation in beak types. Charles Darwin would be amazed at how far his initial study has come!
Original Article
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Tuesday, November 26, 2013
The Genetics of Red Hair
I found it quite interesting to note that the rarest natural
color of hair is red. Scientists have
determined that this is due to the mutations on a gene known as MCIR.
In the 1990’s, scientists focused their research on chromosome 16 and
one of its genes, MC1R.
The MC1R gene
is located on the long (q) arm of chromosome 16 at position 24.3.
Cytogenetic
Location: 16q24.3
Molecular Location on chromosome 16: base pairs 89,984,286 to 89,987,384.
Scientists have determined that individuals with red hair
have more amounts of phaeomelanin than eumelanin. It appears that when there are two mutated
versions of the MC1R gene, the conversions are not as frequent and thus, there is a
buildup of phaeomelanin in the pigment cells.
This results in red hair and fair skin, prone to freckles and an
increased sensitivity to sun exposure.
Additional studies have suggested that variations in the MC1R gene may also increase the risk of
developing melanoma in the absence of UV radiation-related skin damage.
A recent publication, this week, by the managing director of the Scotland’s DNA
project, Alistair Moffat, leads us to believe
that the gloomy climate in Scotland has resulted in the genetic adaptation of
the population of Ireland to produce offspring with red hair. This adaption allows the needed absorption of
Vitamin D from the sun to maintain a healthy lifestyle. Genetic adaption is quite fascinating and has
been proven to be important in the survival of the human and animal species.
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