So now we know that ecology isn’t just the study of the environment… its studying the interactions between living things and the abiotic and biotic factors of their habitat. Today, we’re going to focus in a little bit more on the relationship between different biotic factors in an ecosystem. These relationships all fall under the category of something called interdependence. Hopefully that rings some bells for you because that was one of the themes of biology & characteristics of life we talked about at the beginning of the year! Interdependence is the idea that every living things relies on other living things one way or another. So lets take some time to dive into these different relationships and understand the concepts behind the interconnectedness. Please watch the video below, take notes, ask questions, and be prepared to discuss the different types of relationships and how living things are connected.
Believe it or not, we actually have was of finding this answer despite the fact the Tyrannosaurus Rex has been extinct for over 65 million years. We can determine a T-Rex features, including taste, using similar features (which we now know are called homologous structures). shared with animals the T-Rex is closely related to.
Recall that yesterday we learned that the more features you have in common, the higher the probability that you share a common ancestor/DNA (the exception would be convergent evolution where two species become increasingly similar despite the fact the originated from different ancestors). So what we can do is plot relatedness, based on characteristics, on a graphic called a cladogram, like the one shown here.
So Today, that’s exactly what we’ll be doing, using the link at the top of this post, you’ll follow the steps to learn how cladograms are created, organized, and what the different branches of it mean. By the time you are through, you will know what it tastes like to bite into a big fat dino-burger!
Since evolution cannot occur before our eyes in a class period, today we’ll be ‘simulating’ evolution with a game and a simulator. For each, their are directions and questions you must answer. Click the image below to be taken to the weblink. (*iPad users: You must download and use the Puffin web browser to run these simulations)
Who Wants to Live a Million Years
Choose variations in a population to try to survive for a million years. Watch out for environmental changes and mutations!
Watch how small changes in populations can have big impacts. You can also change settings to see how these animals would fair when their food source behaves differently.
That’s what we’ve been talking about the last few days. We’ve talked about theories and evidence that supports or refutes those theories. There have been lots of theories of evolution but we’ve focused on two…
- Acquired Characteristics
- Whatever traits or habits that you picked up over your life, you passed on to your children.
- Believed that if you really “needed” something or some habit to survive you could acquire it.
- Descent with Modification – Present living beings are modified decendents of older organisms and species.
- Modification by Natural Selection – Environment limits the growth of populations. Some Organisms have traits that make them better able to survive in their environment
Evidence suggests that Drawin’s theory, which he illustrated in his book “On the Origin of Species”, is accurate. Can you think of any instances of organisms that look like other species but have some type of special advantages to help them survive in their environment?
To review, click through the Darwin information pages and see if you can help a species of furry creatures live for a million years!