In 1983, while studying Drosophila scientists discovered homeobox genes. A homeobox gene can contain a shared sequence that is 180 base pairs or 60 amino acids long referred to as the homeodomain. Homeobox genes have a multitude of functions including regulation of patterns, anatomical development (anterior-posterior), limb differentiation, the binding of DNA, and regulation of transcription. Due to the major role that homeobox genes play when it comes to providing the body plan for animals they are highly conserved evolutionarily. That high conservation has other means in regards to body plans developing over time. Conservation of homeobox genes is done well in segments which is part of the reason we know that there have been two complete
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In fact HOX genes value preservation of their signal order where as the number of the various HOX genes may vary along with how similar they are the order stays constant. Homeobox genes control the patterns but the gradients and their interaction play a vital role in segment formation and specification with even seemingly miniscule changes altering the body plan. The alternation of the homeobox genes tells us that if you look at a fly and a mouse they use the same HOX genes in the same order a mouse simply has a few more. It tells us that genes controlling the eye development in humans and Drosophila are compatible enough that the human gene could be placed in a fly and eyes would develop since downstream genes do the tweaking. Though that does not mean that duplications always made such drastic changes when it comes to body plans. Realism leads to the likely situation of the first changes being deleterious in nature and resulting in death. Or leading to gene silencing and probable functional recapture which is when one change results in the suppression or silence of a certain genes expression with it being possible that later on that function is regained by the reversal of the …show more content…
The little things that allow for differentiation between twins and siblings fall to individual genes that play the role of personalization in humans and result in unique coloring or patterning in animals. While this is taking place on the micro level the macro evolutionary changes are being handled by HOX genes the master organizers themselves. On the macro level changes to the body plan are being made. This is of course not to say that micro and macro evolution work in anything but tandem to keep the multiple developmental processes
In fact HOX genes value preservation of their signal order where as the number of the various HOX genes may vary along with how similar they are the order stays constant. Homeobox genes control the patterns but the gradients and their interaction play a vital role in segment formation and specification with even seemingly miniscule changes altering the body plan. The alternation of the homeobox genes tells us that if you look at a fly and a mouse they use the same HOX genes in the same order a mouse simply has a few more. It tells us that genes controlling the eye development in humans and Drosophila are compatible enough that the human gene could be placed in a fly and eyes would develop since downstream genes do the tweaking. Though that does not mean that duplications always made such drastic changes when it comes to body plans. Realism leads to the likely situation of the first changes being deleterious in nature and resulting in death. Or leading to gene silencing and probable functional recapture which is when one change results in the suppression or silence of a certain genes expression with it being possible that later on that function is regained by the reversal of the …show more content…
The little things that allow for differentiation between twins and siblings fall to individual genes that play the role of personalization in humans and result in unique coloring or patterning in animals. While this is taking place on the micro level the macro evolutionary changes are being handled by HOX genes the master organizers themselves. On the macro level changes to the body plan are being made. This is of course not to say that micro and macro evolution work in anything but tandem to keep the multiple developmental processes