Cannabis Chronicles

We are eventually planning on authoring a more complete version of this “essay”, with additional notes for each numbered “bullet point”. It’s planned that our notes will explain and describe how each point is relevant to cannabis enthusiasts, preservationists and medical users.

Until we can create that “annotated” version, we wanted to at least post the original which was compiled from “Introduction to Conservation Genetics” by R. Frankham, J.D. Ballou, & D.A. Briscoe; Cambridge University Press; © R. Frankham, D.A. Briscoe, Smithsonian Institution (compiled from pages 529-530)

Take home messages from this book

1. The biological diversity of the planet is being rapidly depleted due to direct and indirect consequences of human activities (habitat destruction and fragmentation, over-exploitation, pollution and movement of species into new locations).

2. The major genetic concerns in conservation biology are inbreeding depression, loss of genetic diversity, genetic drift overriding natural selection, population fragmentation, genetic adaptation to captivity and taxonomic uncertainties.

3. Inbreeding and loss of genetic diversity are inevitable in all small closed populations.

4. Inbreeding has deleterious effects on reproduction and survival (inbreeding depression) in almost every species that has been adequately investigated.

5. Loss of genetic diversity reduces the ability of populations to adapt in response to environmental change (evolutionary potential). Quantitative genetic variation for reproductive fitness is the primary component of genetic diversity involved in adaptive changes.

6. Genetic Factors generally contribute to extinction risk, sometimes having major impacts on persistence.

7. Ignoring genetic issues in the management of threatened species will often lead to sub-optimal management and in some cases to disastrous decisions.

8. The objective of genetic management is to preserve threatened species as dynamic entities capable of adapting to environmental change.

9. The first step in genetic management of a threatened species is to resolve any taxonomic uncertainties and to delineate any management units within the species. Studies using genetic markers can typically aid in resolving these issues.

10. Genetic management of wild populations is in it’s infancy and is not generally adequate or optimal to ensure long term viability (largely because genetic issuers are ignored).

11. The greatest unmet challenge in conservation genetics it to manage fragmented populations to minimize inbreeding depression and loss of genetic diversity. Translocations among isolated fragments or creations of corridors for migration are required to minimize extinction risks. Concerns about possible outbreeding depression (often exaggerated) have discouraged translocations this address the impacts of population fragmentation.

12. Captive breeding provides a means for conserving species that are incapable of surviving in their natural habitats. Captive populations of threatened species are typically managed to retain 90% of their genetic diversity for 100 years, using minimization of kinship.

13. Genetic deterioration in captivity resulting from inbreeding depression, loss of genetic diversity and genetic adaptation to captivity, reduces the probability of successfully reintroducing species to the wild.

14. Population sizes of Ne much greater than 50 (N>500) are required to avoid inbreeding depression and Ne = 500-5000 (N = 5000-50,000) are required to retain evolutionary potential. Many wild and captive populations are too small to avoid inbreeding depression and loss of genetic diversity in the medium term. ( i.e.. - Ne is the symbol used to represent the concept of “effective population . . . N in this case is used to represent the estimated actual population needed to produce the indicated Ne).

15. Molecular genetic analyses contribute to conservation by aiding detection of illegal hunting and trade, and by providing essential information on unknown aspects of species biology.

16. Genetic factors represent only one component of extinction risk. Wild populations face threats from deterministic factors (habitat loss, over exploitations, introduced species and pollution) that contribute to population declines, and stochastic factors (demographic and environmental stochasticity, catastrophes and genetic stochasticity) that become increasingly important in small populations. Genetic factors typically interact with other factors.

17. The combined impacts of all ‘non-genetic’ and genetic threats faced by populations can be assessed using population viability analysis (PVA). PVA is also used to evaluate alternative management options to recover threatened species.

We trust you have found this book informative, thought-provoking and interesting and that it will assist in your future conservation activities. The Earth’s biodiversity is being lost at a frightening rate, and we must act now to conserve our life support system. We encourage you to participate in this wide ranging activity, as an enormous task lies ahead.

Hopefully posting these “essential” points on the conservation / preservation of genetics, this brief synopsis of the primary points made “Introduction to Conservation Genetics” by R. Frankham, J.D. Ballou, & D.A. Briscoe; Cambridge University Press will serve to generate thought and conversation, and help pave the way for future explorations on this topic.

If these introductory points were interesting to you, then we would suggest that you invest in the following textbook which we consider to be THE essential introduction to the field of Conservation Genetics: “Introduction to Conservation Genetics” by R. Frankham, J.D. Ballou, & D.A. Briscoe.

It’s a wonderful resource for any serious preservationist, here’s a brief description of the text:

The biological diversity of our planet is being depleted due to the direct and indirect consequences of human activity. As the size of animal and plant populations decrease, loss of genetic diversity reduces their ability to adapt to changes in the environment, with inbreeding depression an inevitable consequence for many species. This textbook provides a clear and comprehensive introduction to the importance of genetic studies in conservation. The text is presented in an easy-to-follow format with main points and terms clearly highlighted. Each chapter concludes with a concise summary, which, together with worked examples and problems and answers, emphasise the key principles covered. Text boxes containing interesting case studies and other additional information enrich the content throughout, and over 100 beautiful pen and ink portraits of endangered species help bring the material to life.