Evolution Blog

Through sexual selection, some species of animals may compete with each other for the chance of reproduction. This can be seen in various ways but one category is through male-male competition One type of male-male competition is seen through combat between the male species. This is where the individual directly fights for the females. This can be seen in zebras.  Zebras are grouped into harems where there is one dominant male with as many as 6 females and their foals in the group. It has been observed that they engage in combat each other for females and will even go as far as stealing females from one another. The fights between males can be very intense and can possibly end in death. The males will to bite the others neck and legs and the fights between them can last for long periods of time. Another type of male-male competition is exhibited through sperm competition. This has been observed in stink or shield bugs. These insects will have a prolonged copulation period that pr...

When looking at fossil records, if no homologous samples are available and you must rely just on analogies samples how accurate can this be in predicting the species' sexual dimorphism? This is confusing me to because if there is nothing similar to the extinct species currently,  then how can it be accurately compared? One interesting concept discussed in the podcast was that scientists do not completely know or understand why females prefer a specific trait over another. This concept is still heavily debated but consist of indirect or direct benefits that the female may gain from the males. 

1. Are individuals ever put into the wrong species? & what happens if this mis-categorization occurs? 2. If two species never come into contact with each other, how is it decided that they are two different species or the same one? 3.Is there ever an individual that does not fit into any species?

  my little cousin carter :)

  In a population of bugs that experience genetic drift , a tornado comes and RANDOMLY kills all of the purple bugs but allows the blue and pink to survive and repopulate. This does not mean that the pink or the blue bugs are more FIT, but genetic drift is a process that happens randomly that does not selective for the "most fit" species.  

Phenotypic plasticity is the ability of an individual to change its phenotype to be better fit and thrive in a certain environment  In the paper analyzing lizard's phenotypic plasticity, it was seen that there was a difference in coloration in lizards living on the lava flow versus away from the lava flow. In order to determine this, they looked at 104 different individuals and  found two  regulators of melanin production which were PREP and PRKAR1. It was seen that in l izards away from the lava flow , in both regulators they were homozygous for the AA alleles. In the lizards on the lava flow, they exhibited different frequency of the alleles in the regulators as seen below when analyzing the lizards on lava flow, they exhibited 35% AC and 60% AA in the PREP regulator and 45% AG and 55% AA in the PRKAR1A regulato r This figure shoes the a bility of the lizard's phenotypic plasticity by lizards away from the lava being transported to living in the envi...