Chapter 9

6 Pages
Unlock Document

Environmental Science
Carl Mitchell

Chapter 9Biodiversity and Conservation Biology Our Planet of Life y Biological diversity or biodiversity is the sum total of all organisms in an area taking into account the diversity of species genes population and communitiesBiodiversity encompasses several levels Species diversity y Species is a distinct type of organism a set of individuals that uniquely share certain characteristics and can breed with one another and produce fertile offspring o They are categorized by common ancestors and ability to breed y Species diversity is the number and variety of species in the world or region y Species richness is the number of species y Evenness or relative abundance is the extent to which numbers of individuals of different species are equal or skewed y Taxonomists scientists who classify species use an organisms physical appearance and genetic makeup to determine its species Genetic diversity y Genetic diversity encompasses the varieties in DNA present among individuals within species and populations y According to Environment Canada genetic diversity is what enables a species to adapt to ecological change y In the long term population with more genetic diversity may stand better chances of persisting because their variation better enables them to cope with environmental change y Populations with depressed genetic diversity may also be more vulnerable to disease and may suffer inbreeding depression which occurs when genetically similar parents mate and produce weak or defective offspring Ecosystem diversity y Ecosystem diversity refers to the number of variety of ecosystems but biologists may also refer to the diversity of biotic community types or habitats within some specified area Some groups hold more species than others y Some groups have given rise to many species in a relatively short period of time through the process of adaptive radiation y Others have diversified because of a tendency to become separated by barriers that promote allopatric speciation Measuring biodiversity is not easy y Our knowledge of species numbers is incomplete for several reasons o First some areas of Earth remain little explored o Second many species are tiny and easily overlooked o Third many organisms are so difficult to identify that some thought to be identical sometimes turn out once biologists look more closely to be multiple species
More Less

Related notes for EESA01H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.