Please Do Now: 1) Define ecological niche 2) Brainstorm some unique features of the “urban ecosystem” (ex: lots of tall buildings)

 Do Now  Data Analysis Intro  What is Evolution?  Polar Bear Adaptation Video

 You will be a presented a series of graphs and charts (every Thursday)  For each chart or graph, on a blank sheet of paper you will answer 1-2 questions.  Once we have gone through all of them, you will be posed a question that unifies all the figures. Respond in 3-4 sentences.

 1) What is the long term trend in the size of the polar bear populations?

1) What month were these scientists measuring sea ice in? Over what time period? 2) What is the overall trend in sea ice coverage?

 1) How does a decline in the number of seals affect the number of polar bears?

 1) Is the polar bear decline uniform throughout its range?  2) Where are polar bears better studied? Russia or the U. S. and Canada?

 Based on the graphs you have seen, what do you think the fate of polar bears will be in the future? Why do you think this is? (Cite specific examples from the graphs).

 CHANGE OVER TIME in the characteristics of a POPULATION (a group of organisms of the same species)  Does not happen on the individual level!  Usually occurs very slowly over hundreds and thousands of years.

 YES: To refer to a group of organisms in the same area or sharing the same traits. (There is a population of Black Squirrels in McCarren Park).  NO: As a number (The population of Squirrels in McCarren Park is 200)

 Homologous structures  Common Ancestry  Adaptation  Many more reasons

 Common Ancestry is the idea that all life evolved from an original single celled organism about 4 Billion Years Ago  Ever since then, single species have been diverging to form 2 separate species from 1, because of natural selection.

 Are features in different species that show evidence for evolution from a common ancestor because they have similar shapes and compositions.  Example: the limbs of very unrelated animals all have the same bones.

 An adaptation is a trait (characteristic) that has a functional role in the life of an organism  Developed and maintained in a population by natural selection  Without it, the organism would not be as well suited to its niche

 As an exit ticket, please identify 3 adaptations the polar bear has to its environment, and explain how they are adaptive. (You can do it on the bottom of your data analysis page).