Humans and the Environment The Effects of Homo sapiens on the Biosphere, Extinctions and Conservation Biology

Recall our discussion on the first day? The human animal – Homo sapiens – has a profound impact on the earth and its inhabitants No kidding! Let us return to some of these issues/questions and categorize the impacts

Humans are a natural member of the communities on earth. There are two rather different responses to this statement and really the question is based on the foundation of humans as a natural part of the community and again… Are we a part of the natural community? Think about this from the perspective of any dominant species in an ecosystem – Are we doing things differently than any dominant form in another ecosystem?

One of our most important issues The effect of the humans on biodiversity When we look at biodiversity, we can really look at diversity on three levels: –Genetic diversity – long term effects? –Loss of species diversity – what is the level of influence? –Loss of ecosystem diversity The loss of a single population can lead to losses at all three levels – How?

What are the major threats? Really, we can enumerate four: –Habitat destruction –Exotics –Overexploitation –Disruption of Food Chains Think about these effects on a local scale Do these effects remain on a local scale or are they felt far beyond?

Population size and extinctions The damages to populations do not have to include total elimination of the population, simply a reduction beyond a critical level Why is this the case? Think about this from the limited number of mates, then inbreeding and loss of variability which in turn results in lowered fitness in the population and a downward spiral

What are our basic needs? Can we list the basic needs? Between basic needs and where we are today, something has happened. Can you identify some of the issues associated with our behavior? If we can identify the problems, we can solve them, right? What are the potential barriers to resolution of some of these issues?

Break into groups of 4 or 5 Each group should come up with either popular or your own ideas about conservation strategies Take about 10 minutes and then I will ask each group to present one of their ideas to the class