Maddy's Evolution Blog

  In most species, the male is usually more elaborate while the female is more drab and picky about her mate. This is often because the females are the ones that put more energy into offspring both by producing the egg and in parental care. Microphis deocata  are the opposite. The female is more elaborate while the male is more drab and picky about his mate. This could suggest that the male provides more parental care to the young than the female. Pipefish  biology supports this hypothesis because the males have a brood pouch. After the male fertilizes the eggs, the female deposits them into the male's pouch where they remain until they hatch about 15 days later.  Sound familiar? Seahorses are very similar with the male carrying the eggs in a pouch, a trait that possibly evolved in a common ancestor since both seahorses and Microphis deocata are part of the Syngnathidae family. However, unlike in pipefish where the eggs are fertilized in the female, in seahorses, the...

Kimura's theory of neutral evolution and the theory of evolution are both ways of explaining how evolution occurs. The theory of natural selection says that individuals which are not well suited for an environment are less likely to reproduce than those that are well adapted. This leads to a population becoming more adapted to the environment assuming that the traits being selected for are heritable. For example, if you have a population of mice where 50% of the mice are brown and the other 50% are white. The white mice are much easier for hawks to see which makes the brown mice better adapted to the environment. After one generation the ratio might change to 75% brown mice and 25% white mice and after two generations it might be 90% brown mice and 10% white mice. After several generations, the population will either become 100% brown mice or closer to 95-99% brown mice depending on if brown fur color is a dominant or recessive trait.  Kimura's theory of neutral evolution says ...

  Image credit: https://medium.com/@GrrlScientist/rock-paper-lizard-the-evolutionary-dynamics-of-reproductive-strategies-grrlscientist-b9c716273feb Resources: https://www.smithsonianmag.com/science-nature/the-lizards-that-live-rock-paper-scissors-118219795/

I remember learning in Organismic Biology that female Daphnia are able to reproduce sexually or asexually. When the environment is ideal and unchanging the Daphnia reproduce asexually because this form of reproduction produces offspring that are colones of the parent and if the environment is perfect for the parent it will be perfect for colones of the parent. However, when the environment is changing and the conditions are less ideal the female Daphnia will reproduce sexually with the males because this leads to offspring that are more genetically diverse giving them a better chance of being able to survive and reproduce in the new environment.  Given this example, it seems logical that there are benefits to inbreeding not only in Daphnia but in other organisms as well. One benefit would be passing on beneficial recessive alleles, however, the chances of the offspring being homozygous recessive for an allele that decreases fitness is also increased. Another benefit, and cost, woul...

  I feel that I have a much better understanding of how mutations and genetic drift affect populations. In my original blog post, I said that I considered evolution to be both a fact and a theory depending on the context. I would now change that to say that evolution is both a fact and a theory regardless of the context because it is a fact that evolution occurs and the theory is the explanation for why evolution occurs. I also defined evolution as "... how living organisms adapt to a changing environment over generations and how these adaptations can lead to the formation of new subspecies." I would change my definition to say that evolution can occur in each generation. An example being how the average relative beak size of Darwin's finches changed every year depending on if natural selection favored birds with larger or smaller beaks.  I understand that genetic drift has a larger impact on smaller populations but I am confused as to why a beneficial mutation doesn'...