Presentation is loading. Please wait.

Presentation is loading. Please wait.

Uncertainty in Biology. At least we can be certain that evolution is true. These two have told us.

Similar presentations


Presentation on theme: "Uncertainty in Biology. At least we can be certain that evolution is true. These two have told us."— Presentation transcript:

1 Uncertainty in Biology

2 At least we can be certain that evolution is true. These two have told us.

3 At least we can be certain that evolution is true. Many scientists disagree! Also it depends on what you mean by “Evolution”! Causes confusion! 1. “Macro” evolution by spontaneous natural process – order from chaos 2. “Macro” evolution guided by designer Creation not requiring an evolution process –In other words Darwinian evolution is just one of several hypothesis or models to explain the untestable past

4 At least we can be certain that evolution is true. 1. Also as scientists we need to distinguish between “Macro” and “Micro” evolution.

5 At least we can be certain that evolution is true. 1. Macro evolution e.g. humans originated from lifeless chemicals! e.g. humans originated from lifeless chemicals! 2. Micro evolution e.g. Peppered moth adapts to environment e.g. Peppered moth adapts to environment BUT – it is still a moth!! (so why is it used as evidence of macro evolution in text books?!) BUT – it is still a moth!! (so why is it used as evidence of macro evolution in text books?!)

6 At least we can be certain that evolution is true. Amongst the scientific community there is a great deal of scientific scepticism of Neo-Darwinism: Public Statement has currently over 700 signatures Of these a significant number are “Young Earth” scientists

7 They used science to demonstrate it. 1. Have a hypothesis. 2. Make observations and measurements. 3. Make suggested conclusions based on data. 4. Peer review. 5. Reject or accept hypothesis.

8 We can be certain because: The fossil record.

9 Fossils give us intermediate forms (fish to tetrapod transition).

10 Darwin’s Enigma Darwin’s Enigma –“The geological record is extremely imperfect and this fact will to a large extent explain why we do not find intermediate varieties, connecting together all the extinct and existing forms of life by the finest graduating steps. He who rejects these views on the nature of the geological record, will rightly reject my whole theory.” –Charles Darwin, The Origin of Species…….

11 Fossils give us intermediate forms (fish to tetrapod transition). “ fossils such as Acanthostega are regarded by some evolutionary palaeontologists as ‘missing links’ not because they are, but because they are believed to be. As Patterson says, it is ‘in the mind’, because ‘missing links’ are a philosophical necessity—to somehow provide ‘proof’ for their evolutionary faith” Andrew Snelling BSc (Hons), PhD Andrew Snelling BSc (Hons), PhD

12 Artificial Selection

13

14 A Pigeon You get the picture! And……… Another Pigeon erm!...is it a Pigeon by any chance? Another Pigeon

15 Big Dog Little Dog They are both still dogs!

16 All life has things in common. DNA (the universal code in living organisms) DNA (the universal code in living organisms) Amino acids Amino acids Proteins Proteins

17 All life has things in common. Indeed…..much as a designer may utilise a common platform in his designs, so nature seems to have been created using a common set of genetic instructions. Indeed…..much as a designer may utilise a common platform in his designs, so nature seems to have been created using a common set of genetic instructions. –Why not re-use certain proteins in different species…that makes perfect sense from an intelligent design point of view?

18 Vestigal organs. What is the appendix for? What is the appendix for? Why have we still got it? Why have we still got it? Is there selection pressure to have a larger one? Is there selection pressure to have a larger one?

19 Vestigal organs. ‘vestigial’ : an organ that once was useful in an animal’s evolutionary past, but that now is useless or very close to useless. ‘vestigial’ : an organ that once was useful in an animal’s evolutionary past, but that now is useless or very close to useless. The list of vestigial organs in humans has shrunk from 180 in 1890 to 0 in present day. The list of vestigial organs in humans has shrunk from 180 in 1890 to 0 in present day. –Bergman and Howe, 1990

20 Vestigal organs. So what of the apparently useless appendix? So what of the apparently useless appendix? The appendix is part of the immune system, strategically located at the entrance of the almost sterile ileum from the colon with its normally high bacterial content The appendix is part of the immune system, strategically located at the entrance of the almost sterile ileum from the colon with its normally high bacterial content

21 Predictable Biogeography Marsupial distribution – why? Marsupial distribution – why? Out-competed everywhere else by placental mammals Out-competed everywhere else by placental mammals

22 Evolution can be observed in the process of speciation. E.g. Drosophila E.g. Drosophila

23 Imperfections – why would a creator produce imperfect organisms E.g. Blind spot in the eye. E.g. Blind spot in the eye.

24 Imperfections – why would a creator produce imperfect organisms Eye often used (by Dawkins for example) to argue that there can’t be an Intelligent Designer since the eye has a flawed design! Eye often used (by Dawkins for example) to argue that there can’t be an Intelligent Designer since the eye has a flawed design! However….it is merely ignorance of eye’s physiology that leads to such a conclusion! However….it is merely ignorance of eye’s physiology that leads to such a conclusion!

25 Imperfections – why would a creator produce imperfect organisms The blind spot does not reduce vision quality. The blind spot does not reduce vision quality. Each eye sees a slightly different visual field; large areas overlap. Each eye has a blind spot where the optic nerve passes through the retina to reach the brain, this blind spot falls on a different place in each retina. Each eye sees a slightly different visual field; large areas overlap. Each eye has a blind spot where the optic nerve passes through the retina to reach the brain, this blind spot falls on a different place in each retina. Info from both eyes is then combined so that these visual blind spots are not normally perceived. Therefore because the other eye fills in the gap, special tests are normally required to even notice it. Info from both eyes is then combined so that these visual blind spots are not normally perceived. Therefore because the other eye fills in the gap, special tests are normally required to even notice it. (He and Davis 2001). (He and Davis 2001).

26 Intelligent Design: Irreducible Complexity 40 different complex protein components Absence of any one of these causes the rotor to fail! Therefore all parts will have had to evolve simultaneously in order to produce a functional advantage to the bacteria….unlikely! Therefore an Intelligent Designer needed.


Download ppt "Uncertainty in Biology. At least we can be certain that evolution is true. These two have told us."

Similar presentations


Ads by Google