Simple explanation of macroevolution?

Definitions can vary but basically;

Macroevolution is the production of new genes or genetic information. You would need this to evolve from microbes to man, and lots of it; at least a thousand fold increase.

Microevolution is change within the existing gene pool, often defined as a change in allele frequency in a population over time. This can result in speciation within the existing kind (i.e. genera or family. There have been some cross genera crosses).

Microevolution does not create any new genes and so no amount of microevolution will ever add up to macroevolution. It is a qualitative difference rather than a quantative difference so if 2+2=4 is microevolution then 200+200=400 is still microevolution, since that is a mere quantative difference.

You will also note that speciation is the result of microevolution rather than macroevolution. An example is the London Underground Mosquito, a new species but still a mosquito.

You might want to look at the following:

http://www.talkorigins.org/faqs/comdesc/

"29+ Evidences for Macroevolution"

Although for most biologists there is only evolution, the Creationists have used what was once really an obscure term to argue there are "flavors" of evolution: microevolution and macroevolution. There is only evolution, although the sub terms have gotten into popular use and even some biologists are using the terms.

It's like saying there is a difference between 2 + 2 = 4 and 200 + 200 = 400 in terms of the process.

Wikipedia has a nice essay on this word.

If you think about it, there is no mechanism in nature that prevents evolution from happening all the way to speciation, once you have unequal genetic individuals in populations, time, and usually geographical separation of populations.

Macroevolution is a term used to differentiate evolutionary changes that are different from those termed microevolution. Macroevolution is changes that result in the appearance of new species or higher taxon, such as genus, family, order, class, phyla and kingdom. Microevolution is changes that are found within a species. For example, the change in hair texture and skin tone in human populations are considered microevolutionary changes. That means humans with straight hair and light skin tones are considered the same species as people with dark skin and curly hairs. OTOH, macroevolution are changes that change us into humans from an ape ancestor. For example, we walk on two legs instead of four. This trait distinguishes us from closely related genera such as Pan and Gorilla, both of which walk on 4 legs.

There is no process that allows a species to change into another genus or higher taxonomic rank because these ranks are recognized on the basis of morphological disparity between groups of organisms and they are the result of numerous speciation events and extinction events that create the differences between groups of organisms. That means a species does not evolve into another genus or another family when it evolves into a different species. Instead, when a lineage undergoes many different speciation events over the course of millions, tens of millions or even hundreds of million years, then the organisms within that lineage may look and/or function so differently than other lineages that the organisms are classified into another taxon.

Both macroevolutionary and microevolutionary changes are the results of changes in the genes of course. The difference is whether these changes will result in a change in a species' adaptation to the environment. If the changes affect drastically an animal's adaptation, then natural selection will act negatively on the interbreeding of individuals that have the new changes and those that don't. Take our ancestor for example. When they started evolving on the savanna, one of the first behavioral changes they made was to walk on 2 legs. That in turn favored any mutations that made 2 legged walker more efficient and more comfortable. Once these mutations happened, any of these apes that go back and hybridize with the old species will have offsprings that are less well adapted to 2 legged walking. Therefore the necessity to walk on 2 legs eventually resulted in the reproductive isolation between 2 populations that used to be the same species. The isolation meant that these 2 populations are 2 different species. Millions of years later, scientists will claim that macroevolutionary changes have occurred. Not only are these two populations become 2 different species, but additional changes, such as the loss of body hair, enlargement of the skull and a weakening of the jaws have resulted in the placement of the bipedal apes to be referred to as hominids or humans. Not only is a new genus proposed by many have classified humans in a different family than the apes.

Macro is a larger study of micro or Quantum which includes natural aging and advanced communications.