You will have to explain to me what you mean by “horizontal gene transfers”. This sounds to me like simple micro evolution within a species.
For instance why is a house cat not the same size as a tiger? Both are of the same species.
Life is amazingly adaptive but species remain a species.
HGT is a process whereby one organism obtains genetic information from another organism (same species or different) without being the offspring of it. A common example of this would be a virus inserting its genetic code into a human being, which in some cases can then become part of our genetic code.
For instance why is a house cat not the same size as a tiger? Both are of the same species.
That's not what this article is about, but FYI the domestic cat is Felix catus whereas the tiger is Panthera tigris. They're not only different species, they're also members of different genera and subfamilies of the Felidae family.
Life is amazingly adaptive but species remain a species.
Well you can say that, but you'd be hard pressed to find anyone familiar with evolution who would agree with you.