HYBRIDS - THEIR ROLE IN EVOLUTION

 During the class about taxonomy and binomial nomenclature we introduced the definition of species. Many of you brought up the subject of hybrids and questioned if they were considered species or not. Most hybrids are not fertile descendants,so in this case, neither  their progenitors are considered members of the same species nor are they accepted as new species. Nevertheless cross reproduction and the appearance of hybrids is one of the fastest ways of creating new species on the planet and therefore play a vital role in evolution. It has always been known to be frequent in plants. These are considerd new species if they are fertile, reproduce and begin to conquer and adapt to their ecosystem.

 After talking about this in class I came across this national geographic article which I think may be of your interest. Click on the following link to read about this interesting topic!

National Geographic Ligers, zorses, and pizzlies: How animals hybrids happen

REAL IMAGES OF REAL CELLS!!

 What we see with the microscope is usually very different to the picures of cells in books.

If we look at a prokaryotic cell under an electron microscope we will see an image quite different to the picture in our science book. At first we may think that it doesn't correspond at all to what we have studied. After some time and if we look at it in detail, eventually we will probably be able to identify the different parts, like the genetic material dispersed in the cytoplasm and even the ribosomes. Look at this picture.

Now clik on this link to see an interesting presentation about prokaryotic cells: 

--------------> SLIDE PLAYER -PROKARYOTIC CELLS