EVOLUTION

Think/Discuss:

I believe new species form when an individual from an already established

species has a change in DNA that is significant enough that it prevents its from

breeding with the original species.  Some species evolve into so many different ones

because each time that species evolves, it is in an ideal location which allows the species to thrive. There are constantly mutations with the species that allows it to evolve and become new species. 

 

 

 

Do:

Harvard Animation: http://outreach.mcb.harvard.edu/animations/preloaderGators.swf

• A common ancestors evolved to several different types of species from the order Crocodilia

• These differences happen because animals in parts of world are under different selective pressure

• The same animal in different environments will evolve differently

• Human intervention causes an impact on evolution

• An example is alligators that live in wet areas will evolve to have a long tail which is better for swimming but alligators that live in dry areas will evolve to have a short tail which is better for running

• This leads to 2 new species

• If species don’t adapt their traits quickly in response to change in the environment, instead of evolution extinction will occur 

 

 

 

 

 

 

 

 

 

 

 

Watch/Make Notes:

 

The Speciation Song- https://www.youtube.com/watch?v=WDPsZPKSEFg

 

• Gene pool isolation leads to creation of new species

• For example if a barrier is made separating an entire species in half there is a gene flow barrier

• Natural  selection will take place and allele frequency will change

•  To figure out if a new species is made, the individuals of the 2 groups need to get it on and if they can successfully reproduce then the species is still the same, if they can't then a new species is created

 

The Speciation Song Explained- https://www.youtube.com/watch?v=PKb8Yi5xzhE

•  Organisms that can successfully breed with each other are considered to be part of the same species and have the same gene pool

• If there is a barrier preventing members of the same species from going to each other, then each gene pool is considered to be isolated from each other 

•  If the conditions of the sides of the barrier are different,  then certain alleles or traits will be better (for example in a cold environment an allele providing a lot of fur is better and will supplement long term survival)

• Through Natural Selection a new species may be created

• Mechanism Isolation is when the genitals are no longer compatible

• Gamete Incompatibility is when the sperm cell cannot fertilize the egg

•  Hybrid Inviability is when the offspring doesn’t survive

•  Hybrid Infertility is when the offspring is infertile 

 

Species- https://www.youtube.com/watch?v=YCoEiLOV8jc

• Salamanders were separated 10 million years ago and they are the same species but now have different features

• They look different and after some millions of years they will become new species

• This is because the new environments those Salamanders were in forced the salamanders to adapt to that environment and changed their allele frequency and colour to hide from predators

 

Reflect/Journal:

This section involved a lot of concepts as well. There were a lot of complex words such as prezygotic mechanism and reproductive isolating mechanism. Understanding those concepts were really difficult but eventually they began to make sense. I really liked how there was a video explaining the song. Normally songs can be really confusing but the video explaining the song helped tremendously. The analogy used in the chapter was also really helpful because it helped explain speciation well. I found allopatric speciation really cool because it basically states that when a species is kept in different locations they will adapt to that location. That just sounds really magical to me which if why I am really interested in it. I mentioned this in the last reflection and I will mention it again and it is the human influence on evolution in this case speciation. Although it can be a good thing that we're essentially creating a new species which contributes to biodiversity, the fact is we are still ruining homes that belong to animals. That isn't fair because we are basically using these animals to suit our needs.