Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?

Study Questions:1. What is a “morphological species", and what are two problems that arise when we use this method for identifying species?

A morphological species or ‘morphospecies’ is a group identified by how they look – their morphology. In some cases, like fossils or museum specimens, no information about their reproductive biology may be known, so morphology may be all we have to classify a group (species). There are obvious problems, however. One is the problem with ‘sibling species’; these are groups that are reproductively isolated but morphologically indistinguishable. Polymorphic species provide another problem – these are single reproductive groups that contain several morphologically different forms. In both cases, morphology is not a good correlate of biological uniqueness.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.

Biological species are “groups of reproducing organisms that are reproductively isolated from other such groups.” Using this definition, however, how can we classify asexual species – is each clone a different species? Likewise, what if we don’t know the reproductive biology of the group? In addition, the very process of speciation is often continuous, such that diverging populations have increasing degrees of reproductive isolation, but may hybridize at some level. At what point in this continuum do we assign members to two different groups/species?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.

Pre-zygotic: geographic, temporal, behavioral, mechanical, chemical

Post-zygotic: genomic incompatibility, hybrid sterility, low hybrid fitness

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, and K Ar decay has a half-life of 1.3by, how old is it?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, and K Ar decay has a half-life of 1.3by, how old is it?

Well, in 1.3by half of the Potassium (K) would change, creating a ratio of 1:1 of Ar:K. Then it would take another 1.3by for half of the remaining K to change. At this point, ¾ of the original K has changed to Ar, for a ratio of 3:1 (¾ : ¼ ). Then, in another 1.3by, half of the remaining ¼ K would change… creating a ratio of 7/8 Ar to 1/8 K.… so 3.9by.

1.3by 1.3by1.3by

KK

Ar

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics?

Astrophysicists have suggested that the earth was spinning more rapidly in the past, such that an earth year 380 million years ago had 400 days in it. Fossil corals, radioactively dated to 380 million years, have 400 daily layers in each annual cycle; corroborating the prediction and radioactive dating.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?

They have an intermediate morphology (characteristics of two major groups), and there exist in the fossil record where evolution predicts they should be: after the ancestral group and before the derived group. So, Archeopteryx is after other reptiles in the fossil record (even after other feathered reptiles), but before true birds that flew.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?

It has a fish-like tail (bony struts) but feet; and it is in the right place in the fossil record.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil?

They have fingers, a bony tail, and teeth like reptiles, but flight feathers like birds. And they are in the correct place in the fossil record.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil? 9. What characteristics do therapsids have that make them intermediate fossils?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil? 9. What characteristics do therapsids have that make them intermediate fossils?

They have intermediate dentition (very primitive specialization like mammals), they walk like mammals (“elbows” in), and they have an intermediate jaw structure composed of several bones like reptiles. And they are in the correct place in the fossil record.

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil? 9. What characteristics do therapsids have that make them intermediate fossils?10. What characteristics do Australopithecines have that make them intermediate fossils?

Study Questions:1. What is a 'morphological species", and what are two problems that arise when we use this method for identifying species?2. State the 'biological species concept', and state three problems that may arise when we employ this definition.3. List five pre-zygotic isolating mechanisms and 3 post-zygotic isolating mechanisms.4. If a rock has a ratio of Ar:K of 7:1, how old is it?5. How has dating from radioactive decay been corroborated by predictions from astrophysics? 6. What are the two key characteristics of transitional fossils?7. Why is Ichthyostega considered to be an intermediate fossil?8. What characteristics make Archaeopteryx an intermediate fossil? 9. What characteristics do therapsids have that make them intermediate fossils?10. What characteristics do Australopithecines have that make them intermediate fossils?

They are bipedal like humans, but have a chimp-like skull in size and shape. And they are in the correct place in the fossil record.