Darwin lived in a time where natural selection was a strange theory among scientists and researchers. This was especially true when other researcher Lamarck argued that organisms passed on helpful traits to their offspring, that they magically could form a new trait to adapt to their environment and then pass it onto their offspring. For example, if a giraffe was too short to reach food, it would grow a larger neck in its lifetime and then pass that trait onto its offspring. Darwin argued that, through the process of survival of the fittest, that short giraffe would die off and never receive the chance to pass on its shortness to future populations. Thus, taller giraffes would survive— they can reach food, shorter giraffes can’t— and the short genes would disappear. The fact that Darwin was introducing a new theory that nobody was used to at the time was peculiar, so he had few people on his side until long after his observations.
Another problem Darwin had was the lack of technology. To travel, Darwin would have to use boats to reach far away places, and of course, this took time.
The final problem Darwin had was the extra time it took for evolution, a process that can take up to millions of years. Evolution didn’t occur over night— it took time for Darwin to conduct experiments, observe, conduct them again, come to a conclusion, and so on.
Hope this helped a little!
Answer:toxic
Explanation:
A ureotelic organism excretes excess nitrogen as urea. Urea is less toxic and needs less water in comparison to Ammonia. Ureotelic organisms include cartilaginous fish, few bony fishes, adult amphibians and mammals including humans. The uricotelic organism excretes uric acid or its salts
Answer:
Euhaline ⇒ Polyhaline ⇒ Mesohaline ⇒ Oligohaline
Explanation:
Let's first define each of these levels:
- Polyhaline: a category of salinity that has medium-high levels of salt
- Mesohaline: a category of salinity that has medium levels of salt
- Oligohaline: a category of salinity that has low levels of salt
- Euthaline: a category of salinity that has high levels of salt
Now, we can order these in decreasing order of salinity:
Euhaline ⇒ Polyhaline ⇒ Mesohaline ⇒ Oligohaline
