https://padlet.com/brooke_weidman/zwt5xf3zxacd en-us 2017-06-08 15:51:26 UTC 2025-10-05 15:35:38 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Rafaelo.png brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176118595 Hippos likely evolved from a group of anthracotheres about 15 million years ago, and the first whales  evolved over 50 million years ago. Hippos are the closest living relatives of whales, but they are not ancestors. It is also believed that whales evolved from creatures that were once able to walk on land as well.]]> 2017-06-12 15:31:52 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176118595 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176122208 The transition from early whales from land to water happened in a series of predictable steps. For example, the evolution of the blowhole. Random genetic changes resulted in a least one whale having nostrils placed farther back on its head. Those animals with this adaption would have been better placed in a marine lifestyle. Such animals would have been more successful and had more offspring. In later generations, more genetic changes occured, moving the nose farther back on the head. Other body parts of early whales also changed, front legs disappeared, their bodies became more streamlined, and they developed tail flukes to better propel themselves through water. ]]> 2017-06-12 15:56:01 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176122208 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176269027 Mutations can be caused by random errors in DNA replication or repair, or by chemical or radiation damage. Mutations can be harmful or neutral. If this happens, it will become more prevalent in the next generation and spread throughout the population. For example, legs started to disappear from whales and their bodies became more streamlined. ]]> 2017-06-13 15:24:04 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176269027 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176273313 Conditions on land may have forced the whales to spend more time in the water. They also could have had a hard time finding food on land. The water may have offered them a place to cool off and to find food to survive on. Over time, their limbs changed to offer them more control over their movements in the water. As the atmosphere temperatures began to change, evolution took place. During certain times of the year, the water was too cold for the whales to survive because they are warm blooded. Therefore, the patterns of migration evolved. ]]> 2017-06-13 15:50:46 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176273313 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176482024 An example of Divergent Evolution during whale evolution would be the Ambulocetus and Maiacetus stage, they were related species becoming less similar over time. 
An example of Parallel Evolution during whale evolution would be the Rodhocetus and Takracetus stage because they came from different species that evolved to be similar due to lifestyle. 
An example of Convergent evolution would be a Mesonychids and Cetacea because they are organisms with different ancestors that became more alike. ]]> 2017-06-15 01:44:44 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176482024 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176483171 Sexual Selection is passing on of the genetic information that is influenced by male competition and female choice. This all started when whales limbs began to change due to weather conditions over time. ]]> 2017-06-15 01:57:37 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176483171 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176483864 Whales are believed to have evolved from creatures that were once able to walk on land. Over time, weather conditions and food sources made whales evolve from land to the water. I chose this topic because I love whales and I wanted to know how they evolved over time. ]]> 2017-06-15 02:04:36 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176483864 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176488077 Genetic Drift is when in each generation, some whales by chance leave behind a few more whales than other individuals. The genes of the whales in the next generation will be the genes of the lucky whales and not the healthier or better individuals. ]]> 2017-06-15 02:52:30 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176488077 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176488909 Vestigial Organs are structures in some organisms that seem to have no use in one species but are useful in another species An example of this would be the pelvic bones in Baleen whales.  These are not useful to dolphins but they also have this body structure. ]]> 2017-06-15 03:02:58 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176488909 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176489621 Molecular evolution is differences in molecular similarities that can be used to determine degrees of relationship between different species. An example of this in the evolution of whales would be that whales are closely related to ungulates ]]> 2017-06-15 03:13:22 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176489621 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176490405 Ontogeny Recapitulates Phylogeny is when organisms during embruological development go through their evolutionary stages. An example of this would be how whales evolved over time due to natural selection. ]]> 2017-06-15 03:23:17 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176490405 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176491041 Homologous Structures are parts that are similar in structure but have different uses in different species. An example of this would be dolphins and whales, they have similar parts such as a blowhole but they use it for different uses. ]]> 2017-06-15 03:31:12 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176491041 brooke_weidman https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176491327 The conditions on land may have forced whales to spend more time in the water. Over time, the water offered more than land did. The water offered a place to cool off and provided more food for the whales to have. Over time, whale's appendages changed to offer them more to do. During certain times of the year the water was simply too cold for the whales to survive due to them being warm blooded. Thus, the process of whale evolution began. ]]> 2017-06-15 03:34:54 UTC https://padlet.com/brooke_weidman/zwt5xf3zxacd/wish/176491327