{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Speciation160-page10 - habitat Today we often discuss loss...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Methods of Speciation - 10 Both gradualism and punctuated equilibrium have merit. Evolution can, and does, result from selection pressures. Evolution also takes place in "jumps" consistent with punctuated equilibrium and random events. The differences are in the interpretation of the forces that shape evolution, not in process of evolution as the underlying foundation of biology. Extinction Before we leave the subject of life, just as we have new species, we have species that decline in numbers and eventually die out altogether. We discussed a several examples of successful adaptations in this section. What about species that lack adaptations in their environment, and lose to those who are better adapted? Adaptations can affect not just populations of one species, but natural selection can also lead to the loss of a species by extinction. When we look at extinction, the most significant cause of extinction is change in
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: habitat. Today we often discuss loss of habitat, but this loss is generally not a physical loss of geography, but a change in that habitat which results in an area no longer suitable for the individuals who originally lived there. Humans have done much in the past few centuries to alter habitat, to the detriment of thousands of species. Species that have narrow gene pools (are highly specialized) and/or have restricted distribution are more vulnerable to changing environments. Those who are large-dimensioned and have greater resource demands are more vulnerable. Equally vulnerable are species perceived by humans as physically threatening, in particular the large carnivores, and most particularly cats, wolves and bears. Karner Butterfly – Lupine restricted Devil's Hole Pupfish – One Nevada Location...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern